A. Field of Art
Described herein are compositions and methods that can prevent corrosion. More specifically, the compositions and methods described provide corrosion prevention of metal submerged in salt water and metal used in crude oil pipes.
B. Description of the Related Art
Corrosion is the inevitable gradual destruction of material, usually metal, by chemical reaction with its environment. These metals are mainly iron and steel, although many other metals may corrode as well. This corrosion is typically due to oxidation, which can be accelerated in the presence of moisture, to form a metal oxide. Many structural alloys corrode merely from exposure to moisture in the air, but the process can be strongly affected by exposure to certain substances. For example, when iron is exposed to moist air, it reacts with oxygen to form rust, Fe2O3nH2O. Coating the surface of the iron-containing article may help to shield the article from the elements needed for the natural rusting reaction to begin.
Corrosion can be concentrated locally, or it can extend across a wide area more or less uniformly corroding the surface. Because corrosion is a diffusion controlled process, it occurs on exposed surfaces. The problem with iron as well as many other metals is that the oxide formed by oxidation does not firmly adhere to the surface of the metal and flakes off easily causing “pitting” and/or “cracking.” Extensive pitting and/or cracking may eventually cause structural weakness, a decrease in luster, a decrease of electrical conductivity, and a disintegration of the metal. Because of this structural disintegration and weakening, the effects of corrosion may cost millions of dollars each year, with much of this loss from the corrosion of iron and steel.